ISO 14644-1

How to choose the right cleanroom chair and seating

Q: What resistance to ground must an ESD cleanroom chair have?

To DIN EN 61340-5-1 the path from the person via the chair to the floor is typically 10⁵ to 10⁹ Ω. Upholstery, frame and casters must form one continuously conductive chain.

Cleanroom seating must match the cleanroom class and must not shed particles itself. This guide explains the choice between PU and stainless steel upholstery, ESD capability to DIN EN 61340-5-1 and why low-abrasion casters matter for each ISO class.

5 minStand: 2026-07Geprüft: Technical editors

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ISO 3-8

cleanroom classes per 14644-1

10⁵-10⁹ Ω

ESD resistance to ground

PU / stainless

low-particle upholstery

0 seams

no particle traps

Inhalt

Cleanroom class and chair
PU or stainless upholstery
ESD capability
Casters and base
Frequently asked questions

Which chair suits which ISO cleanroom class?

The cleanroom class to ISO 14644‑1 defines how few particles a chair may release. The lower the ISO class (ISO 3 to ISO 5), the stricter the demands on upholstery, frame and casters. In higher classes such as ISO 7 and ISO 8, easy-clean plastic upholstery is often enough, while ISO 5 and below are dominated by seamless stainless steel and PU solutions.

It is not just the material that counts but the construction: closed surfaces, no exposed foam edges and as few seams as possible where particles and micro-organisms can collect. In electronics manufacturing, ESD capability is almost always a second, equally important requirement.

Check the documented cleanroom class of your area before you buy. An ISO 8 chair does not belong in an ISO 5 zone, while an ISO 4 chair is needlessly expensive for a general assembly hall.

PU or stainless steel - which upholstery is right?

PU integral foam is the standard for most cleanrooms. The foam forms a closed, seamless skin with no textile stitching, is comfortable and can be wipe-disinfected. Stainless steel is used where maximum resistance to cleaning agents, sterilisation or aggressive media is required.

PU integral foam: seamless, comfortable, resistant to alcohol and H₂O₂ disinfection, ideal for ISO 5 to ISO 8.
Stainless steel (304/316): fully particle-free, autoclavable, resistant to aggressive cleaners, first choice for ISO 3 to ISO 5 and pharma.
Sealed-seam vinyl: cost-effective for higher classes from ISO 7 upward.
No fabric, no open foam and no visible seams in critical areas.

Look for silicone-free upholstery and lubricants. In many cleanrooms silicone interferes with coating, bonding and wire-bond processes and is often explicitly prohibited.

ESD workstation

How to link chair, mat and personnel grounding into one system.

Read the guide

Why must a cleanroom chair be ESD capable?

In electronics and semiconductor manufacturing the chair must dissipate static charge in a controlled way. To DIN EN 61340‑5‑1 the full path from the seat via frame and casters to the conductive floor should lie in the range of about 10⁵ to 10⁹ Ω. Only then is the person connected through the chair to the EPA grounding system.

Continuous conductivity is the key: upholstery, gas spring, base and casters must form a closed chain. A conductive seat is useless if the casters insulate. The dissipative floor closes the loop to ground.

The ESD effect only works together with a dissipative floor. On an insulating floor covering even the best ESD chair stays ineffective.

Which casters and bases are suitable?

Casters are the main source of abrasion in a cleanroom. Low-abrasion twin-wheel casters made of cleanroom-grade polyurethane with a soft running surface protect the floor and generate hardly any particles themselves. In high classes or for sit-stand work, load-dependent braked casters or glides make sense.

Low-abrasion PU twin casters: minimal particle wear, quiet running, available ESD-conductive.
Load-dependent braking: the chair locks when you stand up and only rolls under load.
Glides instead of casters: for fixed workstations and the highest cleanroom classes.
Base of polished stainless steel or powder-coated aluminium, low-seam and wipeable.

Match caster hardness to the floor: soft casters for hard floors, harder casters for soft coverings. This minimises abrasion on both sides.

Cleanroom flooring

A dissipative floor is the precondition for the ESD function.

Read the guide

Frequently asked questions

What resistance to ground must an ESD cleanroom chair have?

To DIN EN 61340‑5‑1 the path from the person via the chair to the floor is typically 10⁵ to 10⁹ Ω. Upholstery, frame and casters must form one continuously conductive chain.

PU or stainless steel - which is better?

PU integral foam is seamless, comfortable and sufficient for most classes. Stainless steel is fully particle-free, autoclavable and the first choice for ISO 3 to 5 and pharma areas with aggressive cleaning.

Are ordinary office chairs acceptable in a cleanroom?

No. Office chairs with fabric upholstery, open foam and standard casters shed particles and are not dissipative. Only purpose-built cleanroom chairs meet ISO 14644‑1 and the ESD requirements.

Which casters are best in a cleanroom?

Low-abrasion twin-wheel casters of cleanroom-grade polyurethane with a soft running surface. They generate few particles, protect the floor and are available conductive and with load-dependent braking.

Looking for the right cleanroom chair?

We supply cleanroom seating with PU or stainless steel upholstery, ESD versions to DIN EN 61340-5-1 and low-abrasion casters matched to your ISO class.

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Class-matched

Seating for ISO 3 to ISO 8 per ISO 14644-1.

ESD tested

Continuously dissipative to DIN EN 61340-5-1.

Low particle

Seamless PU and stainless upholstery, silicone-free.

Expert advice

Cleanroom specialists help with your selection.